Hi,
Yes, The question really is that simple.
I have just bought a used Cebora Proff 55 plasma cutter as the basis for a cnc plasma table.
This macine has a 3 position power switch on the front for 230v single phase - off - 400v three phase.

I have a heavy duty single phase plug for it. The four wires are Blue, Brown, Black and Yellow/Green. I know the yellow/green is earth/ground and common sense would tell me Blue=nutral and brown=live on a single phase install but just wanted to check with the wise!

Also can i just heat-shrink over the end of the spare wire or should i dissconnect this inside the machine? ie. will there be any power coming back up this wire?

Thanks!